Flux for coating metal baths.



-' UNITED STATES PA ENT oFFIoE JAMES H. mA'nDY, or NEW YORK, N.- Y., AND BRUNO n. SCHUBERT, or WEEHAWKEN, NEW JERSEY, ASSIGNORS TO.'I.HE IOHMANN COMPANY, or NEW YORK, N. Y., A

CORPORATION OF NEW YORK.

FLUX FOR COATING METAL BATHS.

Patented July 4, 1 916.

No Drawing. Application filed February ,2, 1915, Serial No. 5,643. Renewed December 2; 1915. Serial i No. 64,776.

i T all 'wkomc't may concern: Be it known that we, JAMES H. MADDY,

residing at 610 lVest One Hundred and Sixteenth street, New York, county of New York, and State of New York, and BRUNO H. SQHUBERT, residing at 224: Jane street,

lVeehawken, county of Hudson, and State of New Jersey, both citizens of the United States, have invented certain new and useful Improvements in Fluxes for Coating Metal Baths, fully described and represented in the,following specification and the t accompanying drawings, forming a part of the same.

The object of thisinvention is to facilitate the formation of a coating upon metallic articles by immersing in a mOlten bath,

cess of ammonium chlorid upon the surface of a molten bath, and also the process of coating ferrous articles in the molten bath by the joint use of such flux and the'treating of the ferrous articles with a salt of mer cury before its immersion in the bath.

Ammonium chlorid, on account of its cheapness, has heretofore been used as a flux mixed with bran, flour, or other bind ers, with the purpose of protecting thesurface of the molten metal from oxidation; but such aflux produces objectionable charred or inert substances upon the bath, and produces no beneficial effect upon the surface of the article that isdipped into the metal; whereas the compound flux herein described has a materialrcleaning effect upon the metal article, sothat if slight de-.

fects in cleaning exist, the flux removes any oxid upon the surface of the article and the molten metal is thus enabled to adhere perfectly thereto and coats the article thoroughly without permitting the formation of any pin-holes. i

Articles coated with lead, zinc, or alloys 7 of lead and zinc with tin, and especially when the metal is hot the pot to form such a articles of iron or steel, may thus be fur- 'T lllShGd'Wlth an integral coating which promaintains such tects them from rust and protection for a long period. a

'hen new metal is placed in the, pot to be melted it often carries oxids, which tend to attack the surface of'the" articles immerse'd therein; but with the flux described herein, the surface of the article is effectively protected from oxidation, and the molten metal is thus enabled to coat the article more perfectl A The present invention is especially useful in the coating of ferrous articles which have been previously treated with salt of mercury to promote the adhesion of the molten 'metal thereto, as the flux operates to prevent oxidation of the mercury which is formed upon the surface of the article by depositionfrom the salt, when heated by mmersion in the molten bath.

The efliciency of the compound flu'x is due largely to the presence of the zinc chlorid,

which prevents the formation of oxids and.

assists to clean the surface of the article as it is immersed in the molten bath; but zinc chlorid is ten times as costly as ammonium chlorid and is muchmore volatile, so that it is soon dissipated if used alone as a flux.

A great saving is secured by using ammonlum'chlorid in the flux, in much greater proportion than the zinc chlorid, as it prevents the zinc chlorid from vaporizing and enormously reduces the cost of the flux.

The preferred method of preparing and -us1ng the flux is as follows: A flux stock Solution is prepared of zinc chlorid, either 9'0 alone or saturated with'an excess of ammonium chlorid dissolved therein. This solution is poured upon the metal in the melting pot either when cold the fluxis evaporated into a thick black liquor cohering together in a mass, covering not more than one-half "the surface of the molten metal.

That is, only suflicient of the solution is poured into partial covering for the moltenmetal.

commercial ammonium chlorid to form a black or thick liquidcoverlng the entire surfrom one-eighth to one alf of an inch.

To this black mass con-' 'taining zinc chlorid, is then added'sufficient or when melted and p face of the metal in the pot to a depth of When this coating becomes, black and spreads over the entlre surface of the melted metal, the flux is completed, and will last for a week or ten days in constant use. This compound flux is formed more quickly in the pot and spreads more evenly over the surface than a flux formed wholly of ammonium chlorid with such a binder as bran,

of the molten bath to oxidation.

Other fluxes often become useless at th end of a single day through vaporization or the accumulation of oxids, making the flux very heavy, or causing it'to stick to the articles when immersed. The compound flux spreads freely 'upon themolten bath, and

of zinc chlorld.

protects it so effectively from oxidation that the flux does not become clogged with oxids.

From the above description it will be seen that the advantages of usin zinc chlorid are attained without the liab' 'ty to vaporization of the same, and at an expense enormously less than a flux of zinc chlorid would cost.

In H. J. LohmannsPatent No. 990,443

.granted April 25, 1911 for process of'comblning a permeating metallic protective with the surface of ferric articles, a treatment of iron and steel articles with a salt of mercury is described, to render the surface of the article more receptive of lead, zinc and tin alloys; and it is found that the use of meaeve Claims:

1. The process offorming a flux upon a bath of fusible metal as lead, zinc and tin, which consists in applying'a solution of zinc chlorid to the surface of the molten metal insuflicient to cover its surface and adding ammonium chlorid thereto until the mixture covers the surface of the bath.

2.- The process of forming a flux upon a bath of fusible metal as lead, zinc and tin, which consists in applying a solution of zinc chlorid saturated with ammonium chlorid to the surface'of the bath insuflicient to cover its surface, and adding ammonium chlorid thereto until the mixture coversthe surface of the bath. i

3. The process of applying a metal coating to ferrous articles, which consists in coating the surface of the metal bath with a. flux of zinc chloridand ammonium chlorid, then depositing a salt of mercury upon the surface of the ferrous article, and finally passing such rticle with such salt of mercury through the flux into the molten bath.

4. The process of applying a coating chiefly of t lead, to ferrous articles, whichconsists in coating the surface of a molten. lead bath with a flux of zinc chlorid and ammonium chlorid, then depositing a salt of mixed with a salt of mercury, and

the flux claimed .herein is especially advan- :tageous in the coating of sucharticles in a molten bath, as it prevents the oxidation of the mercury and serves to clean any oxidized spots upon the surface of the article, so that a perfect coating ma be formed thereon.

"The process of deposlting the salt of mercury upon such articles is fully set forth in -the said Patent No. 990,443., and does not .needto be described herein, as it forms no part of the present invention.

The efliciency of he flu'x'in every respect is very great, and the advantage due to its cheapness is evident .from the foregoing considerations.

erates as efliciently as a flux formed chie y passing the article through the melted flux into the molten metal. v 6. The process of formmg a flux upon a.

:bath of fusible metal, as lead, zinc, and tin,

which consists first, in applying zinc chlorid to the surface of the metal in quantlty 1nsuflicient to cover the said surface, second,.

evaporating such zinc chlorid until it coheres in a mass, and third, adding ammo- .nium chlorid sufficient to form a thick liquid covering the surface of the metal to a depth of not less than one-eighth of an inch.

In testimony whereof we have hereunto set our hands in the presencev of two subscribing witnesses. v When the fluxis prepared upon the sur- Y .face of the molten metal in the manner de- .scribed above, the zinc chlorid forms less than one-fourth of the entire flux, but 0 4 JAMES H. MADDY. \BRUNOH. SCHUBERT. Witnesses: a J. G. Bummer,

'A. J. RAY. 

